Diffuse Aurora
Diffuse
ff
Aurora
Eric Donovan – Midway Utah – June 21, 2007
1.
2.
3.
4.
5.
6.
7.
8.
Introduction
Where do the particles come from?
How do theyy become diffuse
ff
aurora
Remote sensing the magnetosphere
Unstructured quiet time H+ aurora
Structure in the diffuse aurora
Opportunities for future studies
Final thoughts
Acknowledgements: Stephen Mende, Fokke Creutzberg, Leroy Cogger, Brian
Jackel, Emma Spanswick, Vassilis Angelopoulos, Louni Jussila, Mikko
Syrjäsuo, Noora Partmies, Chuck Carlson, Howard Singer, Trond Trondsen,
Mike Henderson
Henderson, Sandy Murphree
Murphree, Don Wallis
Wallis, Matthieu Meurant
Meurant, NASA
NASA,
CSA, CDAWeb, SSCWeb.
Eric Donovan
June 2007
Diffuse Aurora
A Few Details
Eric Donovan
June 2007
Diffuse Aurora
Images from rom http://spaceweb.oulu.fi/~jussila/aurora/
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
I t d ti
Introduction
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
from - www.aldebaran.cz/actions/2002_aurora/start.html
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Show SNKQ Movie
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
FAST Orbit 05849 - 980213
IES and EES data from CDAWeb
Energ
gy Flux
16
8
0.0
1.6
0
1.2
0.8
0.4
0.0
3.0e8
6
Energy Fllux
Energy (ke
eV)
8
4
2
0
64
Energy Flux
Eneryy (keV)
3e6
0.0
66
68
70
72
(erg/ssec/cm^2)
(eV/cm
m^2/s/sr/eV)
0.0
24
(erg/sec/ccm^2)
0.1
(eV/cm^2/ss/sr/eV)
0.2
Ene
ergy Flux
0.3
74
Magnetic Latitude (Degrees)
Eric Donovan
June 2007
Diffuse Aurora
FAST Orbit 05849 - 980213
IES and EES data from CDAWeb
150
30
0.0
1.6
-90
1.2
0.8
0.0
270
7.0e7
180
Energy Flux
Pitch Angle (De
egrees)
0.4
90
0
-90
64
0.0
66
68
70
72
(erg/ssec/cm^2)
(eV/cm
m^2/s/sr/eV)
Energ
gy Flux
1.2e6
(erg/sec/ccm^2)
0.0
270
Energy Flux
Pitch Angle
e (Degrees)
0.1
(eV/cm^2/ss/sr/eV)
0.2
Ene
ergy Flux
0.3
74
Magnetic Latitude (Degrees)
Eric Donovan
June 2007
Diffuse Aurora
Where do the Particles Come
From?
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
ExB m
2
2 Bx∇B
vD = 2 +
2v || + v ⊥
B3
B
2q
(
Eric Donovan
)
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Enerrgy (keV)
Diffuse Aurora
Eric Donovan
June 2007
Enerrgy (keV)
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
How does this become Diffuse
Aurora?
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
FAST Orbit 05849 - 980213
IES and EES data from CDAWeb
150
30
0.0
1.6
-90
3.0
1.2
2.5
0.8
0.4
1.0
0.5
0.0
-50
-40
-30
-20
-10
radial distance (Re)
0
10
0.0
270
7.0e7
180
Energy Flux
1.5
Pitch Angle (De
egrees)
Kappa
2.0
90
0
-90
64
0.0
66
68
70
72
(erg/ssec/cm^2)
(eV/cm
m^2/s/sr/eV)
Energ
gy Flux
1.2e6
(erg/sec/ccm^2)
0.0
270
Energy Flux
Pitch Angle
e (Degrees)
0.1
(eV/cm^2/ss/sr/eV)
0.2
Ene
ergy Flux
0.3
74
Magnetic Latitude (Degrees)
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Remote Sensing the
Magnetosphere
Eric Donovan
June 2007
Diffuse Aurora
Latitude of equatorward boundary of proton
aurora is highly correlated with magnetic
field
e d topo
topology
ogy near
ea the
t e CPS
C S inner
e edge.
Eric Donovan
June 2007
02
40
02
45
02
50
02
55
03
00
03
05
03
10
03
15
03
20
Diffuse Aurora
80
ML
Lat (Degrees)
70
64
68
47
66
32
64
15
62
0
50
40
30
20
10
0200
30
20
10
0
-10
0230
0300
0330
SYM-H
H (nT)
72
Peak Brigh
htness (R)
gil
Intensity (R)
Bx
400 nT
T
The brightness of the
proton aurora tracks
esk
sudden changes in solar wind dynamic
chu
pressure.
p
essu e.
0400
UT (hhmm)
(hh
)
Eric Donovan
June 2007
Diffuse Aurora
Poleward boundary of the diffuse 630 nm
(Oxygen “Redline”) emissions is an
excellent proxy for the open-closed
boundary.
Eric Donovan
June 2007
Diffuse Aurora
Unstructured Quiet Time H+
Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Structure in the Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Proton (Hβ) auroral fading
before EVERY substorm
onset.
onset
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Questions that need answering!
Frames separated by 3 seconds
Vertical striations on keograms are a
consequence of patches “flashing” on.
Whatever process is on one level
aliasing with 3 seconds & the one
second exposure time.
2007-03-13
Athabasca THEMIS ASI
Eric Donovan
094533
094536
094539
June 2007
Diffuse Aurora
Ath b
Athabasca
Optical
p
Pi2
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Reproduced from Figure 10 in Yamamoto, T., S. Inoue, and C. Meng, Formation of auroral omega bands in
the paired region 1 and region 2 field
field-aligned
aligned current system
system, JGR
JGR, 102(2531-2544),
102(2531 2544) 1997.
1997
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Opportunities for New Studies
Eric Donovan
June 2007
Diffuse Aurora
Questions that need answering!
Proton Diffuse Aurora
Why does proton auroral fading occur in the 20 minutes prior to onset?
Is proton diffuse auroral precipitation structured?
Wh t are th
What
the relative
l ti contributions
t ib ti
off the
th various
i
causes off proton
t precipitation?
i it ti ?
Are inductive electric fields important in proton auroral precipitation near onset?
Are all discrete electron auroral arcs embedded in the proton aurora?
Is there such a thingg as a discrete pproton auroral arc?
Electron Diffuse Aurora
What determines structure in the electron diffuse aurora?
What is the role of CPS turbulence in diffuse auroral structure/brightness?
Develop a relationship between CPS conditions and electron auroral brightness.
Do processes such as BBFs play a role in diffuse auroral brightness?
Is there a diffuse auroral signature of mid-tail reconnection?
Develop a relationship between CPS conditions and electron auroral brightness.
What are the relative contributions of the various causes of electron precipitation?
Why is the poleward boundary of the diffuse electron aurora sometimes so sharp?
Is the redline poleward boundary always a good proxy for the separatrix?
Eric Donovan
June 2007
Diffuse Aurora
Questions that need answering!
094533
Eric Donovan
094536
094539
June 2007
Diffuse Aurora
Questions that need answering!
Frames separated by 3 seconds
Vertical striations on keograms are a
consequence of patches “flashing” on.
Whatever process is on one level
aliasing with 3 seconds & the one
second exposure time.
Show THEMIS-Athabasca
Movie
2007-03-13
Athabasca THEMIS ASI
Eric Donovan
094533
094536
094539
June 2007
Diffuse Aurora
Plasma physical mechanisms of DA precipitation
Athabasca University Geophysical Observatory
Instrument Complement
NORSTAR H-beta Imager
OMTI Multi-Spectral Imager
NORSTAR Rainbow Imager
NORSTAR Denswe
D
A
Array Imager
I
(Narrow
(N
F
THEMIS Panchromatic Imager
OMTI Meridian Scanning Photometer
OMTI Induction Coil Magnetometer
NRCAN Fluxgate (at Meanook)
NRCAN Riometer (at Meanook)
NORSTAR Dense Array Imager (at Legal)
MSP Scan Plane
Fl
Fluxgate
M
Mags
MAGIC
MACCS
DMI
AGI
Athabasca U.
IGPP-LANL
McMac
THEMIS GBO
THEMIS EPO
MEASURE
NRCan
CARISMA
Proposed AUGO Campaign
CGSM/NORSTAR Context
Eric Donovan & Mike Greffen
63.37
62.37
61.37
Slave Lake
Calling Lake
Athabasca
Legal
Edmonton
Red Deer
Calgary
Meanook (very near Athabasca in above map)
Eric Donovan
June 2007
Diffuse Aurora
CHAMP Orbit
Magnetic Midnight
In the following plots I am stepping forward one orbit at a time
starting from an orbit where the satellite passes through the night
side over eastern Russia.
g
The contours show constant PACE latitudes from 50 to 80 degrees
and longitudes separated by one hour of local time.
The orbit is shown in red (projected geographically to the surface
g about. Magnetic
g
which is not too bad for the orbit we are talking
midnight is indicated by the dashed white thick line from 50 to 80
degrees PACE.
Eric Donovan
The black dots indicate fluxgate mags in North America and
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Eric Donovan
June 2007
Diffuse Aurora
Considering just this one day in 2002, had all of the ASIs been operating
that I expect will be operating by 2009 been running….
Champ would have passed though the FOVs of roughly 50 ASIs with one
pass having continuous optical coverage from 55 degrees mlat
(NORSTAR) to the magnetic pole (CHAIN) and passing though the FOVs
of AMISR and PolarDARN.
WE can expect this number of conjunctions for all three SWARM
satellites during most times of year. With three satellites and the quality
off E and
d B observations
b
i
that
h SWARM will
ill provide
id this
hi will
ill b
be an
unprecedented opportunity for studies of auroral eledctrodynamics.
Eric Donovan
June 2007
Diffuse Aurora
Final Thoughts
Eric Donovan
June 2007
Diffuse Aurora
Plasma Physics
What causes the
precipitation??
ECH
Chorus
EMIC
Turbulence
Potential Difference
FL Curvature
MASER
●
●
Eric Donovan
Geospace Remote
Sensing
What can we infer
about geospace from
the diffuse aurora?
OC Boundary
E- CPS inner edge
H+ CPS inner edge
Stretched-dipolar trans
Stretching
H+ pressure
Presence off MHD waves
Presence of waves
●
●
Role in Dynamics
Is the diffuse aurora
“important”?
Loss of low E eLoss of high E eLoss of low E H+
Low of high E H+
Direct role in currents
Conductivity effects
Role in wave generation
●
●
June 2007
Diffuse Aurora
References
Eric Donovan
June 2007
Diffuse Aurora
High Points
Discovery & Early Exploration of the Diffuse Aurora
Rees, M., A. Belon, and G. Romick,
The systematic behvior of H emission in the aurora, PSS, 5, 87-91, 1961.
Petschek., H., and C. Kennel,
Tail flow, auroral precipitation, and ring currents., Trans. Am. Geophys.
Union, Volume 47, 137-138, 1966.
L i A.,
Lui,
A P.
P Perreault,
P
l S.-I.
S I Akasofu,
Ak f and
dC
C. A
Anger
The Diffuse Aurora, PSS, Volume 21, 857-861, 1973
Eather, R., and S. Mende
Airborne Observations of Auroral Precipitation Patterns,
Patterns
JGR, Volume 76, 1746-1755, 1971.
Fukunishi,H.,
Dynamic relationship between proton and electron auroral substorms,
substorms
JGR, Volume 80, 553-574, 1975.
Mende, S., and R. Eather,
Monochromatic all-skyy observations and auroral precipitation
p
p
patterns,
p
JGR, Volume 81., 3771-138, 1966.
Eric Donovan
June 2007
Diffuse Aurora
High Points
Properties of the major relevant plasma populations (mostly the CPS)
Frank, L., Relationship of the plasma sheet, ring current, trapping boundary,
and plasmapause near the magnetic equator and local midnight, JGR,
76(2265 2275) 1971.
76(2265-2275),
1971
Wing, S., Central plasma sheet ion properties as inferred from ionospheric
observations, JGR, 103(6785-6800), 1998.
Friedel, R.,
Airborne Observations of Auroral Precipitation Patterns,
JGR, 76(1746-1755), 1971.
Diffusion mechanisms
Kennel, C., and H. Petchek, Limit on stably trapped particle fluxes, JGR, 71(128), 1966.
Sergeev, V., E. Sazhina, N. Tsyganenko, J. Lundblad, and F. Søraas, Pitch-angle
scattering of energetic protons in the magnetotail current sheet as the
dominant source of their isotropic precipitation into the nightside
i
ionosphere,
h
PSS 31(1147-1155),
PSS,
31(1147 1155) 1983.
1983
Eric Donovan
June 2007
Diffuse Aurora
High Points
Inferring things from diffuse auroral boundaries
A. Lui, C.-I. Meng, and S. Ismail, Large amplitude undulations on the equatorward
boundary of the diffuse aurora, JGR, 87(2385-2400), 1982.
W. Imhof, Fine resolution measurements of the L-ependent energy threshold for
isotropy at the trapping boundary, JGR, 93(9743-), 1988.
V. Sergeev and B. Gvozdevsky, MT-index: a new index to characterize the
configuration of the magnetotail, Ann. Geophys., 13(1093-1103), 1993.
G. Blanchard, L. Lyons, J. Samson, and F. Rich, Locating the polar cap boundary
from observations of 6300 Å auroral emission, JGR, 100(7855-7862), 1995.
E. Donovan, B. Jackel, I. Voronkov, T. Sorirelis, F. Creutzberg, and N. Nicholson,
Ground-based optical determination of the b2i boundary: A basis for an
optical MT-index, JGR, 108(doi:10.1029/2001JA009198), 2003.
Rae, Kabin, Rankin, Fenrich, Liu, Wanliss, Ridley, Gombosi, and De Zeeuw
Comparison of photometer anf glbal MHD determination of the open-closed
field line boundary, JGR, 109(doi:10.1029/2003JA009968), 2004.
Eric Donovan
June 2007
Diffuse Aurora
High Points
Papers from which I learned the most
M. Ashour-Abdalla, and C. Kennel,
Diffuse auroral precipitation, in Auroral Processes, C. Russell Ed., 1977.
V. Sergeev, E. Sazhina, N. Tsyganenko, J. Lundblad, and F. Søraas,
Pitch-angle scattering of energetic protons in the magnetotail current
sheet as the dominant source of their isotropic precipitation into the
nightime ionosphere,
ionosphere PSS,
PSS 31(1147-1155),
31(1147 1155) 1983.
1983
D. Fontaine and M. Blanc
A theoretical approach to the morphology and dynamics of diffuse auroral
zones, JGR, 88(7171-7184),
88(7171 7184), 1983.
D. Fairfield and A. Viñas
The inner edge of the PS and the diffuse aurora, JGR, 89(841-854), 1984.
PN
P.
Newell,
ll Y
Y. F
Feldstein,
ld t i Y.
Y Galperin,
G l i andd C.-I.
C I M
Meng,
Morphology of nightside precipitation, JGR, 101(10737-10748), 1986.
Frey, Mende, Carlson, Gérard, Hubert, Spann, Gladstone, and Immel
The electron and proton aurora as seen by IMAGE-FUV
IMAGE FUV and FAST,
FAST GRL,
GRL
28(1135-1138), 2001.
Eric Donovan
June 2007